Chapter 3

1. Requirements Modeling Chapter 3

2. Phase Description • Systems analysis is the second of five phases in the systems development life cycle (SDLC) • Uses requirements modeling and enterprise modeling to represent the new system • Before proceeding to the next phase, systems design, you will consider system development strategies

3. Chapter Objectives • Describe systems analysis phase activities and the end product of the systems analysis phase • Understand joint application development (JAD) and rapid application development (RAD) • Explain how systems analysts use a functional decomposition diagram (FDD) • Describe the Unified Modeling Language (UML) and explain use case diagrams and sequence diagrams

4. Chapter Objectives • List and describe system requirements, including outputs, inputs, processes, performance, and controls • Explain the importance of scalability in system design • Use fact-finding techniques, including interviews, documentation review, observation, questionnaires, sampling, and research

5. Chapter Objectives • Define total cost of ownership (TCO) and explain the concept • Conduct a successful interview • Develop effective documentation methods to use during systems development

6. Introduction • This chapter describes requirements modeling techniques and team-based methods that systems analysts use to visualize and document new systems • The chapter then discusses system requirements and fact-finding techniques, which include interviewing, documentation review, observation, surveys and questionnaires, sampling, and research

7. Systems Analysis Phase Overview • Uses models and other documentation tools to visualize and describe the proposed system • The deliverable is a system requirements document Figure 3-2

8. Systems Analysis Phase Overview • Systems Analysis Skills • Analytical skills • Interpersonal skills • Team-Oriented Methods and Techniques • Joint application development (JAD) • Rapid application development (RAD)

9. Joint Application Development • User Involvement • Users have a vital stake in an information system and they should participate fully • Successful systems must be user-oriented and users need to be involved

10. Joint Application Development • JAD Participants and Roles Figure 3-4

11. Joint Application Development Figure 3-5

12. Joint Application Development • JAD Advantages and Disadvantages • More expensive and can be cumbersome • Allows key users to participate effectively • When properly used, JAD can result in a more accurate statement of system requirements, a better understanding of common goals, and a stronger commitment to the success of the new system.

13. Rapid Application Development • Is a team-based technique that speeds up information systems development and produces a functioning information system • Relies heavily on prototyping and user involvement • Project team uses CASE tools to build the prototypes and create a continuous stream of documentation

14. Rapid Application Development • RAD Phases and Activities Figure 3-7

15. Rapid Application Development • RAD Objectives • To cut development time and expense by involving the users in every phase of systems development • Successful RAD team must have IT resources, skills, and management support • Helps a development team design a system that requires a highly interactive or complex user interface

16. Rapid Application Development • RAD Advantages and Disadvantages • Systems can be developed more quickly with significant cost savings • RAD stresses the mechanics of the system itself and does not emphasize the company’s strategic business needs • Might allow less time to develop quality, consistency, and design standards

17. Modeling Tools and Techniques • CASE Tools Figure 3-8

18. Modeling Tools and Techniques • Functional Decomposition Diagrams • A top-down representation of business functions and processes • Also called structure charts

19. Modeling Tools and Techniques • Functional Decomposition Diagrams Figure 3-9

20. Modeling Tools and Techniques • Unified Modeling Language • A widely used method of visualizing and documenting software systems design • provides various graphical tools and techniques, such as use case diagrams and sequence diagrams

21. Modeling Tools and Techniques • Unified Modeling Language Figure 3-10

22. Modeling Tools and Techniques • Unified Modeling Language Figure 3-11

23. Modeling Tools and Techniques • Unified Modeling Language Sequence Diagram Figure 3-13

24. System Requirements Checklist • System requirement • Five general categories • Outputs • Inputs • Processes • Performance • Controls

25. Future Growth, Costs, and Benefits • Scalability • A scalable system offers a better return on the initial investment • To evaluate, you need information about projected future volume for all outputs, inputs, and processes

26. Future Growth, Costs, and Benefits • Total Cost of Ownership • In addition to direct costs, systems developers must identify and document indirect expenses that contribute to the total cost of ownership (TCO) • Microsoft has developed a method for measuring total costs and benefits, called Rapid Economic Justification (REJ)

27. Fact-Finding • Overview • Although software can help you to gather and analyze facts, no program actually performs fact-finding for you • The first step is to identify the information you need

28. Fact-Finding • Who, What, Where, When, How, and Why? Figure 3-15

29. Fact-Finding • The Zachman Framework • A model that asks the traditional fact-finding questions in a systems development context

30. Fact-Finding Figure 3-16

31. Interviews • Systems analysts spend a great deal of time talking with people • Much of that time is spent conducting interviews • Consists of 7 steps

32. Interview • Step 1: Determine the People to Interview • Informal structures • Step 2: Establish Objectives • Determine the general areas to be discussed • List the facts you want to gather

33. Interviews • Step 3: Develop Interview Questions • Creating a standard list of interview questions helps to keep you on track and avoid unnecessary tangents • Avoid leading questions • Open-ended questions • Closed-ended questions • Range-of-response questions

34. Interviews • Step 4: Prepare for the Interview • Careful preparation is essential because an important meeting and not just a casual chat • Limit the interview to no more than one hour • Send a list of topics • Ask the interviewee to have samples available

35. Interviews Figure 3-18

36. Interviews Figure 3-19

37. Interviews • Step 5: Conduct the Interview • Develop a specific plan for the meeting • Begin with good introduction • Use engaged listening • Allow the person enough time to think about the question • Summarize main points • After interview, summarize the session and seek a confirmation

38. Interviews • Step 6: Document the Interview • During the interview, note taking should be kept to a minimum • After the interview, record the information quickly • After the interview, send memo expressing appreciation, including the main points discussed so the interviewee has a written summary and can offer additions or corrections

39. Interviews • Step 7: Evaluate the Interview • In addition to recording the facts obtained in an interview, try to identify any possible biases • Unsuccessful Interviews • No matter how well you prepare for interviews, some are not successful

40. Other Fact-Finding Techniques • Document Review • Observation • Seeing the system in action gives you additional perspective and a better understanding of the system procedures • Plan you observations in advance • Hawthorne Effect

41. Other Fact-Finding Techniques • Questionnaires and Surveys • Keep the questionnaire brief and user-friendly • Provide clear instructions that will answer all anticipated questions • Arrange the questions in a logical order, going from simple to more complex topics

42. Other Fact-Finding Techniques • Questionnaires and Surveys • Phrase questions to avoid misunderstandings; use simple terms and wording • Try not to lead the response or use questions that give clues to expected answers • Limit the use of open-ended questions that are difficult to tabulate

43. Other Fact-Finding Techniques • Questionnaires and Surveys • Limit the use of questions that can raise concerns about job security or other negative issues • Include a section at the end of the questionnaire for general comments • Test the questionnaire whenever possible on a small test group before finalizing it and distributing to a large group

44. Other Fact-Finding Techniques • Sampling • Systematic sample • Stratified sample • Random sample • Main objective of a sample is to ensure that it represents the overall population accurately

45. Other Fact-Finding Techniques • Research • Newsgroups • Site visit Figure 3-23

46. Other Fact-Finding Techniques • Interviews versus Questionnaires • When you seek input from a large group questionnaire is a very useful tool • If you require detailed information from only a few people, then you probably should interview each person • Interview is more familiar and personal • Questionnaire gives many people the opportunity to provide input and suggestions

47. Documentation • The Need for Recording the Facts • Record information as soon as you obtain it • Use the simplest recording method • Record your findings in such a way that they can be understood by someone else • Organize your documentation

48. Documentation • Software Tools • CASE tools • Word processing • Spreadsheets • Databases Figure 3-24

49. Documentation • Software Tools • Presentation graphics • Personal information managers

50. Preview of Enterprise Modeling • At the conclusion of requirements modeling, systems developers should have clear understanding of business processes and system requirements • The next step is to model the logical design of the system